A myositis-specific autoantibody profile is sent in a 7-year-old girl with juvenile dermatomyositis who has extensive subcutaneous calcification on radiographs. Which antibody is classically linked to calcinosis in juvenile dermatomyositis?
- A Anti-MDA5
- B Anti-Jo-1
- C Anti-NXP2 ✓
- D Anti-SRP
Correct answer: C. Anti-NXP2
Explanation
Anti-NXP2 antibodies are strongly associated with calcinosis cutis in juvenile dermatomyositis and are among the commonest myositis-specific antibodies in children. Anti-Jo-1 marks the antisynthetase syndrome with interstitial lung disease and mechanic hands, while anti-SRP produces severe necrotizing myopathy; neither predicts calcinosis. Anti-MDA5 relates mainly to rapidly progressive lung disease rather than calcified deposits.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.